INTRODUCTORY LECTURE ON THE OBJECTS AND NATURE MEDICAL SCIENCE: DELIVERED In the Hall of the Medical Department of Transylvania University, On the 3d day of November, 1841, BY ELISHA BARTLETT, M. D. Professor of the Theory and Practice of Medicine in Transylvwue University. LEXINGTON, KT. K. L. & J. W .FINNELL, PRINTERi. 1841. CORRESPONDENCE. MEDICAL DEPARTMENT, | November 10, 1841. ) Prof. E. Bartlett. Respected Sir:—We, the undersigned, were appointed by the members of the Medical Class, a committee to request in their behalf a copy of your In. troductory Address for publication. We are further instructed to express to you the united sense of the Class in the deep feelings of admiration which its delivery inspired— the universal high appreciation of your profound professional research and refined accom- plishments, and the unbounded gratification which your recent accession to the institu- tion has created. Permit us, sir, in performing this agreeable duty, to add our undivided assurances of the highest esteem and friendship. WILLARD F. TAFT, J JAMh.S T30YKIN, } Committee. JNO. PATTERSON, \ Llxikgtom, Novemblb 10, 1841. Gentlemen:—In compliance with your request, I herewith transmit to you a copy of my Introductory Address. I beg you to receive for yourselves, and to express to the Class, my sincere acknowl- edgments for the kind and complimentary manner in which you have spoken of myself, personally, and of my lecture;—and my assurances, also, that so long as I shall have the honor of constituting one of the Faculty of this Institution, my efforts shall oe earnest and constant for the promotion of its interests, and for the welfare of its pupils;—espec- ially in inculcating sound, philosophical and practical principles in medicine, founded, exclusively, on the accurate observation and the rigorous analysis of appreciable phenom- ena; and in opposing the adoption and spread of those multiform and hypothetical sys- tems of pathology and therapeutics, which have ever exerted, and which still continue to exert so disastrous an influence upon that noble science and that beneficent art, to the cultivation and practice of which our lives are to be devoted. I am, very truly, your friend, ELISHA BARTLETT. To Messrs. W. F. Taft, J. Boykjn, J. Patterson. LECTURE. It becomes me, in this place, and at this time, to make this, my first utterance, which in all honesty and sincerity I now do, a hearty ex- pression of thanks to my colleagues, and to the honorable members of the board of trustees of Transylvania University, for their kind con- sideration and regard in calling me to the responsible station which I here occupy; and to pledge to them, which in like honesty and sincerity 1 now do, and to the service of the Institution with which they are con- nected and over which they preside, the full consecration^of such ability as has been vouchsafed me. Gentlemen of the Medical Department of Transylvania University:— I am to teach the Theory and Practice of Medicine; and I propose to devote this, the first hour of our official relationship, as teacher and pupils, to an explicit statement of my own conceptions of some of the fundamental duties which belong to my department. Tho subject of my Introductory Lecture will be this: — The Nature of the Science and the Art of Medicine. I shall endeavor to show you in what this science and this art consist;—to define their true meaning;—to as- certain, if possible, and to mark out their legitimate boundaries and relations. Considering the miscellaneous and, to a great extent, the non pro- fessional character of my audience, I might, perhaps, have availed my- self of the very proper and legitimate usage of occasions like the pres- ent, and have chosen some topic for discussion, more generally inter- esting in itself, and especially more intelligible to those of my hearers who are not supposed to be familiar with matters of a strictly scien- tific or professional nature. Under different circumstances, I might have followed my tastes and inclinations in this respect, but coming before the University for the first time, as a teacher of science, I have felt myself constrained, by the circumstances of my position, to confine myself to a subject of a strictly scientific and professional character, and among those which offered themselves for my selection, I cannot im- 4 agine one more appropriate to the present occasion than that which I have chosen;—I do not know any that is more important. I do not propose to occupy your time with any account of the par- ticular objects, and of the relations to each other, of the several primary departments of medical science, such as anatomy, physiology, pathology, therapeutics,&c.—These subjects are matters of elementary instruction; they are generally recognized, well established, and well understood; so that they can hardly fail, even if they are not formally stated, either in books or in lectures, either by myself or by my colleagues, of be- coming familiar to you. I have another object, and that is—to repeat, in substance, what I have already said, to ascertain the essential and true character of medical science; to find out in what it consists; what are its elements; what are its objects of investigation, and what the true methods are by which we can attain them. In short, and in the plainest possible words, in this our peculiar province of Practical Medi- cine, what is it that we wish to know? what is it that we can know? and what are the true and best means of arriving at this knowledge? The development and illustration of the idea, thus variously and em- phatically expressed, will constitute the business of my lecture. There is a very wide difference, so far as this matter is concern- ed, between all the other sciences and our own. In all the others, the legitimate objects of research are well ascertained; and the true and only efficient methods of investigation are universally admitted and agreed upon. The objects and nature of the several sciences are set- tled. The direction which should be given to our powers of research is fixed, and the limits, within which they are necessarily restrained, are already defined. In medicine this is far enough from being the case. There is no general and clear conception of the real nature and the legitimate objects of medical science, and of the best means of at- taining these objects: there is no common and strong conviction in the minds of medical men of the essential character of the science and the art with which they are concerned. But further,—to a very great extent not only are the nature and the objects of medical science but dimly and obscurely understood, they are wholly misunderstood. Our science, to a degree, far greater, I appre- hend, than many of us are aware of, is still corrupt with the scientific and philosophical vices of alchemy, for instance, during the middle ages. An enormous amount of intellectual labor is annually expended upon the solution of problems in medicine as utterly idlo and visionary, as entirely without the domain of legitimate science, as were those of the universal solvent and the elixir of life. If these opinions are sound, 5 and my conviction that they are so, is as entire and settled as any that my mind ever entertained, the importance, nay the necessity of endeav- oring to correct and to establish our notions must be obvious enough. Before I proceed to announce, in the shape of a formula, or to de- fine in set terms, the objects and nature of medical science, it may, perhaps, prepare our minds for an easier and more distinct comprehen- sion of the subject, if we look, for a moment, at some of the other sciences, the objects and nature of which are so much better ascertain- ed and agreed upon. With the light of analogy, derived from these, we shall readily dispel much of the darkness which yet envelopes our own. Among these sciences there is no other one so closely and so vari- ously related to medicine as chemistry. It is very intimately connected with many of the processes that are carried on in the living economy, so that it becomes an efficient handmaid of physiology; and it furnishes us with many of our most potent remedies of disease. For these, and for other reasons, it makes up a part of all thorough systems of medi- cal instruction, and every medical man is supposed to be more or less conversant with it. Now, let us propound the same questions in rela- tion to chemistry, the solution of which, in relation to medicine, con- stitutes the subject of this lecture. What is the nature of Chemistry? What are its objects? What does it aim to accomplish, and by what means? Manifestly this: — to ascertain the phenomena which result from the action upon each other of the ultimate atoms of the different substances of which the material world is composed; and of the action, also, upon these atoms, of certain other bodies or agents, such as heat, light, electricity. The object of the science, I say, is to ascertain their phenomena, to analyze, classify and arrange them. It is manifestly this, I repeat it, and no other. The molecular particles of which the different kinds of matter are composed, when presented to each other, or when brought into the closest attainable neighborhood to each other, so act and re-act upon, combine with and modify each other, as to im- part and acquire an almost infinite variety of new properties. It is the object of chemistry to investigate the laws and the results—the phenom- ena—of these combinations—these actions and reactions. This is its legitimate and appropriate end:—It has no other. Let us look, in the same way, at that beautiful domain lying along the confines which seperate the department of strict physical from that of chemical science-shading off into the two, by delicate and impercepti- ble gradations, like the colors of its own spectrum into each other,— occupied by optics. What are the objects of this science? What are it. 6 aim and end? What does it profess to do, and by what means and in- strumentalities does it work? Manifestly, again, its purpose is to in- vestigate and ascertain the phenomena of light:—its composition—its properties—its relations to the various forms of matter. These phenom- ena, like those of chemistry, after they have been ascertained and verified by experience, it arranges and classifies, and these classifica- tions of the phenomena, constitute the laics or principles of the science. It would be easy to extend this kind of illustration—it would be easy to carry it through the whole circle of the physical and natural sciences; but we have gone far enough, perhaps, to answer our present purpose. In these and in all, the great, leading, legitimate purpose of the science— whatever it may be—its end and aim^-consist in the investigation and ascertainment of the actual phenomena with which the science is con- cerned ; and in the analysis and arrangement of these phenomena in natural and convenient classes. The true purpose of all medical science differs, in no respect, from that of the other sciences. I shall speak only of that department to which our own investigations are to be more particularly confined. The chair which I occupy and the branch which we are to study is de- signated by the title of "The Theory aud Practice of Medicine." It embraces the entire natural history of disease, and the best methods for its mitigation and removal. Its legitimate object is the investiga- tion and ascertainment of all the phenomena of morbid action—the re- lations of these phenomena to each other, and to their causes—and, also, to those substances and agents in nature which are endowed with the property of influencing and modifying them. It is possible enough, that this announcement may seem to you, after all this apparent flour- ish of trumpets, no very momentous or important affair; but let me as- sure you, that, simple as it may seem, you will find it to be a principle pregnant, like all true principles, with almost infinite results. You will find too, as we go along in our course, that it has always been and that it still is, very extensively—with some qualification, I might say almost universally, disregarded. Let me repeat it. The great purpose of that department of medical science, with which we are concerned, its appropriate and legitimate end is this:—to study and to ascertain the actual, appreciable phenomena of morbid action—the reciprocal re- lations of its multifarious and manifold modifications—with the influ- ences which excite, and with the substances and agents which are ca- pable of modifying it. In this investigation of these phenomena and of these relations; and in their arrangement and classification, does the science of our department consist. T I have said that the doctrine, which I have thus stated, is very far from being generally recognized and acted upon, by the members of our profession; that it is not received and admitted as a practical and operative principle, as it is in the other sciences; and that, therefore, there is great need for insisting upon its truth and its importance. I do not mean, however, to say that it is wholly denied or disregarded, or that it is not now and has not always been, to a considerable extent, admitted and acted upon. So far as our science is at ail a science. So far as our art is of any real service to humanity, it is in consequence of following this true and only legitimate mode of research. What 1 mean to say is this: that the principle has never been generally and fully recognized, and that it has never, except in a few instances, been thoroughly carried out to its entire and genuine results. I mean to say, furthermore, that not only have the true nature and objects of medical science been but imperfectly and impartially admitted; but that there has been mixed up, even with this imperfect and partial recognition of the truth, an all pervad- ing and enormous amount of misapprehension and error. This misap- prehension and this error you will find running through the entire re- cords of our science, from the time of Hippocrates to the present. Before proceeding any further in the development of my subject, I will explain to you what I mean by these remarks. The error of which I speak grows out of a radical misapprehension of the real and essential character of our science, of its legitimate objects, and of the true methods of attaining them. It consists, substantially, in a depar- ture from the investigation of phenomena arid their relations, and in an indulgence in speculations that can only be characterized by the terms metaphysical or transcendental. In this wrong spirit, under the in- fluence of this mistaken and false view of the nature and objects of medical science—not the phenomena of morbid action—and their real and appreciable relations:—not their ascertainable causes—their recip- rocal action:—their consequences and results:—but their intimate, ul- timate and essential nature—the subtle and inscrutable processes and agencies through which, and by which, they were carried on, became the objects of enquiry. This is the most glaring fact in the history of our science. All the multitudinous and colossal mass of medical literature which in manuscript and in print has been piling up, through the march of ages, bears a running and perpetual testimony to the truth of this assertion. Of the seven thousand volumes, which are marshalled on the shelves of the adjoining library, there is but an in- significant proportion which do not contain the record and the proof of 8 what I say. And the worst of it is, that the evil is but little less uni- versal now than it formerly was. You will find the evidence of it quite as strong in the fresh and plump octavos, with their delicate and embossed covers of cotton and wood, just issued from the Boston and New York presses, as you will in the clasped and ponderous folios of Paris and Geneva. When the actual phenomena of diseases hare been ascertained, by accurate and thorough observation, we next proceed to analyze these phenomena, and to arrange or classify them according to their intimate and obvious relations. This arrangement and classification of the phe- nomena of disease constitute the true laws of disease, the real and ver» itable principles of pathology. The pathological law is identical with the generalization of the phenomena; the two terms of phraseology express precisely the same fact—they mean, exactly the same thing. The universality of the fact is identical with the principle. The same thing is true in all the physical and natural sciences. In chemistry, observation shows that when dissimilar bodies unite in their ultimate atoms, the resulting compound possesses properties un- like those belonging to the original constituents. This is the law of the science, and the law consists, simply, in the expression of a uni- versal fact. In like manner observation shows that these dissimilar atoms unite with each other, in certain fixed quantities or proportions. This constitutes another of the principles of chemical science, but the principle is only the expression of an invariable and uniform series of phenomena. We may have been in the habit of regarding the princi- ple^ the law, as something else than the universal fact, or the invari- able series of phenomena,—as something separate from the latter__be- yond it—above it—superior to it—but if we analyze the matter, we shall find no such thing. The too expressions have but a single mean- ing. It is precisely so with the laws of heat. State them as you please,— mall their infinite and beautiful variety—and you have done simply this, and no more—you have given distinct and formal expression to the existence of a universal fact; you have declared, in the shape of a formula or an axiom, the existence of some certain, fixed, invariable series of phenomena. Even the great and sublime law of attraction or gravity, like those to which I have just referred, is nothing else than the statement of a universal fact. It is important that I should notice a difference—a very great and wide difference,which exists between the more exact physical science., and medicine. If the real nature and objects of the physical science., 9 on the one hand, and of medical science on the other, be, as I have en- deavored to show, essentially alike; if the great purpose of them all is the study and ascertainment of the phenomena with which each is es- pecially concerned—if there 4s no radical and essential difference be- tween them and our own science, how comes it, you will be likely to ask me, that there is such a wide difference between the results to which we have arrived? How comes it, that in the physical sciences, every thing is positive, fixed;—their great laws ascertained and universally admitted, susceptible of expression in determinate axioms, and formu- lae, every where recognized as absolutely and indisputably true; while in medicine, to a very considerable degree, at least, every thing is quite otherwise—doubtful, fluctuating, indeterminate—but few, if any of its laws thoroughly ascertained and universally admitted? This question is a reasonable one, and I will endeavor to answer it. The chief and obvious cause of the difference against medicine and in favor of the other sciences is this: the imperfection of our means of observation. This imperfection is very great—-it meets us on every hand—it runs through every part of our science. It is very difficult— to a great extent it is quite impossible, with these imperfect means of observation, for us to get at the phenomena of disease. We are obli- ged to study certain series, 01 natural groups, or combinations of phe- nomena, in parts, in fragments. Some of these phenomena may be be- yond our reach—others may be fugitive, and not easily appreciated.— Beside this, the phenomena themselves are constantly modified by dis- turbing causes, the nature and operation of which we do not understand. We know only, from the supervention of certain other phenomena, that the disturbing cause is present, but in what it consists, or how it acts, it may be wholly impossible for us to know. The ultimate laws and principles, connected with, and arising from the vital forces, and their relations, are just as absolute and immutable, as those connected with the sciences. A. B. yesterday, was seized with what we call fever and ague. The vital forces, connected with his living or- ganization, had been peculiarly impressed by a series of complex influ- ences, many of them very obscure, and but little or not at all known to us—the result of which was that aggregate and succession of morbid actions, which we call intermittent fever. Most unquestionably, under precisely the same circumstances, the same phenomena would always be found. The difficulty lies here:—the phenomena, with which we have to deal, are so numerous—so obscure—so fugitive—their relations with each other and with their causes are so complex—so subtle—so in- scrutable; and our means of investigation are so partial and imperfect B 10 that even under the most favoring circumstances, when we have done all that we can do to insure accuracy, when we have eliminated from our process, so far as we are able, all possible sources of error, al- though some of our results may be positive, there will necessarily re- main others, more or less doubtful and contingent, while many will have escaped us altogether. I ought not to pass from this part of my subject without adding, that our results in the investigation of disease have been only approximative and unsatisfactory, to a very great extent, not from the inherent diffi- culties of the case, but from our neglect to pursue the only right meth- od, and to avail ourselves of all the means which are really within our reach. I need hardly say to you how entirely different from all this it is in the physical sciences. Look at the chemist. He is sure of his results because he is sureef the circumstances and conditions in the midst of which he produces them. His processes are not liable to be disturbed by the intervention of agencies, which he can neither comprehend, nor control, as is so constantly the case with the physician. Neither time nor place work any changes in his materials nor in their relations.— Berzelius in his cabinet in Sweden, and Professor Peter in his Labora- tory in Lexington, separating a volume of atmospheric air into its ele- ments, know with entire certainty before hand, that their results will be the same. The prism with which Sir Isaac Newton unwove the seven fold web of light, would have given the same results when the bow of promise was first set in the Heavens, and it will continue to do so in all coming time. But, it is important to observe, that this circumstance does not, after all, constitute any real difference in the nature and objects of the two classes of science. The manifold difficulties of investigation in medi- cal science, do not in any way change the objects or the nature of the investigation itself. The phenomena of disease and their relations— these and these only are the legitimate objects of our research—the in- vestigation—the analysis and the arrangement of these alone consti- tute the science of medicine. It is in vain to seek for it any where else. There is one aspect in which the phenomena of the living economy, both in health and disease, approach very nearly in invariableness and absoluteness to those of inanimate matter. I mean when these phe- nomena are considered in great aggregates—on a vast scale. When this is done, we see these laws developing and manifesting themselves, with a majestic regularity, like that which caries the planets round 11 the sun. Nothing can be more doubtful than the duration of life, for instance, in the case of a particular individual, but when the observation of this fact, the duration of life, is extended from one to_a million or to a hundred millions, the average period becomes one of great certainty and correctness. Of two individuals born on the same day, and with ap- parently equal prospects of life, one may finish his career in an hour, and the other may reach the age of a century of years: but of a hundred thousand born in a given continuous period of time, the mean duration of life in the first fifty-thousand, will not probably vary, to any appreciable extent, from that in the second fifty-thousand. The whole science of vi- tal statistics consists of these extensive observations and generaliza- tions. The same process may be applied, to some extent, to the phe=» nomena of disease, and the result will be certain general, approximative laws—laws of degree or proportion, as we may call them. For instance, although nothing can be more uncertain, in the case of an individual, who is exposed to the causes of tuberculous disease, in which side of tne chest, the morbid disposition will commence, still of a very large num- ber, say a thousand, it may very confidently be predicted, that two thirds will have the left lung affected, before the right. In other words observation seems to have established the fact, that in about two thirds of the cases of tuberclous phthisis, the morbid desposition begins in the left lung. This predilection then, of the morbid element for the left lung, may be considered, properly enough, a law of pathology. Similar remarks may be made in regard to very many other morbid phenomena. But we are not to forget, that however absolutely and positively we may express these general laws—when applied to vast aggregates—the practical and actual dealing of the physician is with individual cases:— and that here the law deduced from the great aggregate, as an average or proportionate result, may fail entirely in its application. Such then, according to my apprehension of the subject, is the real character,—such are the legitimate objects of medical science—and such, as I have stated and explained them, the true methods of proce- dure in reaching them. But is this all? Are we to be tied down to this hard and dry study of facts and their relations—to this drudging and sterile investigation of phenomena, and their dependencies? Are we to have no theory of medicine? No system of pathology? Are we never to understand the nature of disease? Are we never to know the modus operandi of its causes and its remedies? Is no attempt to be made to reveal the essential and proximate causes of morbid processes, and the immediate agencies by which these processes are brought a- bout? 12 In answer to these questions, which naturally enough suggest them- selves, I will state to you, as briefly and explicitly as I can, my views upon this branch of the subject of my lecture. I have no objection to theory in medicine. I have no objection to hypothesis. Nay, more, I am willing to admit them here, as they are admitted into the other sciences, in the character of legitimate aids in our search after truth— in our study of phenomena. I have. no.wish to despoil them of a sin- gle right, or to deprive them of a single claim, which they can make good. But I insist on this—as has been done in the other sciences, that these aids of theory and hypothesis be kept in their proper places— and in medicine, most emphatically, these places arc very subordinate and very humble ones. The difficulty has been, and is, that these powers have been placed in the very thrones of the medical realm, and the sceptre has been put into their hands:—it is high time, that these ille- gitimate usurpers were called to make way for the rightful sovereign. The essential elements of science—of all science that is not abso? lutely abstract and metaphysical—arc to be found in the phenomena of the particular science, whatever it may be, and in their various relations. Theory or hypothesis may be admitted, as a more or less probable, a more or less ingenious—a more or less plausible explanation and inter- pretation of these phenomena and of their relations. For instance, as I have already stated, the real and thetrue objects of the science of op- tics is to ascertain the properties and phenomena of light, and its re- lation to the different material substances;, of which the universe is made up. Its sources—its composition—the velocity of its motion— the mode of its transmission from one object to another—the influence exerted upon it by bodies through which it passes—or against which it strikes:-—its relation to heat, electricity and so on—these various phenomena classified and analysed, as far as they can be done—consti- tute the science of optics. But into this science—thus constituted— various theories or hypotheses have been introduced, by which to ac- count for—to explain, and interpret the phenomena themselves. These theories are not phenomena, but assumptions. One is, that light is a natural substance, transmitted, bodily, from all luminous matter. This was the belief Newton. Another is, that.the phenomenon of light is owing to a motion imparted toa subtle and invisible sether. This was the belief of Huyghens. Biot adopted a modification of the same theo- ry. It has also been refined and developed by Dr. Young and Fresnel. The theory in these cases is assumed—entirely a speculation—in the absence of any actual evidence, as a convenient means of explaining the phenomena. This is all well enough. For this purpose there is no 13 objection to a theory. But let it be ever remembered that the sci- ence consists in the actual phenomena and their relations—and not in the hypothetical interpretation of these phenomena and these relations —however ingenious, however probable, however plausible these inter- pretations may be. The science is in the phenomena, not in the hy- pothesis. The latter you may destroy with impunity, or change at your pleasure, and the former will be in no way affected by the operation. It would be very easy to derive precisely similar illustrations from, most of the physical sciences, but the time which I have already occu- pied, and the time which I wish yet to occupy, admonish me to desist, I shall conclude the lecture with a few applications of the doctrine which I have stated to the science of medicine. Here, as in all the oth- er sciences, the legitimate objects of investigation consist of the phe- nomena of disease, and their relations, and theory or hypothesis is to be admitted only as a more or less propable explanation of the phenom- ena. The phenomena are not dependent upon the theory—their exis- tence, their laws, their relations, constituting the science, are wholly and absolutely independent of the explanation or the theory : they re- main, whether the theory be present or away, whether it be sound or false. For instance, there is a very common and very important mor- bid process, to which we apply the term inflammation. What are the legitimate objects of research connected with this process. Manifestly its phenomena—its natural history—and nothing else. We wish to know its relations—its causes—the various forms which it assumes— under different circumstances—in the several organs and tissues—its complications—its terminations—its results—the influence exerted up- on it by remedies and so on. There is only one method of arriving at all these results, and that is by the way of experience—observation.— These results, so arrived at, constitute the science of medicine, so far as inflammation is concerned. It is natural enough, however, that the mind should not rest fully satisfied with this knowledge. We wish to know by what agencies—through what recondite processes, these phe- nomena are brought about. We ask for the secret and invisible chain which somewhere runs through and binds them together. We demand the how and the why of these facts. To answer this end we re- sort to theory and hypothesis; in medicine, just as in optics or dynamics. So in inflammation, we have various theories, or interpretations of the phenomena—explanations of its nature. One theorist says the process consists simply in a morbid augmentation of the natural action of cer- tain vessels—another says it consists in diminution of this action—a third says there is augmented activity in one stage and diminished activ- (4 ity in another—one places the morbid action in one set of vessels—a second in another set—-and so on. It is not necessary that I should de- scribe or enumerate all these theories of inflammation. I wish you to see clearly their true relation to the phenomena: and then you will be able to understand their real value. I wish you to see that they are simple in- terpretations of the phenomena and their relations: and that they have no claim whatever to the high character of constituent elements of science. Many of the pathological laws of phthisis are now well ascer- tained. One of these is this, that the essential pathological lesion consists in the deposition, in the lungs, of an extraneous, morbid matter, characterized by certain physical and chemical properties, to which we give the name of tubercle. This is the law—this is the observed phenomenon—thus constituting an element of science. But what is the nature of the morbid process which results in this depo- sition? How is the deposition to be explained? Here come in our theories. One school of pathologists says, that the tubercular deposite is always the result of an inflammatory process—this is tho opinion of Broussais, Bouillaud, Gallup, Gross, and many others. Another school says there is no evidence of this, and that the deposite is the result of morbid actions not inflammatory. Well! let us explain, interpret, theo- rise—if we will; but let us never forget, that the theory does not con- stitute the science. The investigation of the phenomena constitutes the science and the labor—the theory is only speculation and pas- time. Another pathological law of this disease is, that the tubercle mani- fests a strong predilection for the summit of the lungs. The deposi- tion almost always commences here. It is almost invariably found most advanced in the upper part—in the apex of the lungs. Such is the phenomenon, ascertained by simple experience, so nearly invariable as to constitute one of the most general laws of pathology. Why is this so? Now comes in the theory. There is no obvious reason to be found in the structure of the lungs. There is no light shed upon the subject by analogy. Dr. Morton says, the reason is because the lungs have less motion here than in their lower portions. Well! if he and others are satisfied with this explanation, I have no objection. It may be correct—it may not be. Only let it be regarded as an explanation— as a theory—and no great harm will come from it in any event. I will not multiply these illustrations any further. I have not time to do so; and it could hardly be necessary, even if I had. I hope I have succeeded in making myself understood. I have a strong convic- 15 tion of the soundness and the importance of the views which I have stated, and I shall refer to them often in the course of our future inves- tigations. My relation to you imposes upon me two duties—one of these, the great and leading one, is the clear and full communication of the results of our researches thus far in regard to the phenomena and the management of disease: the other, and it would hardly be extrava- gant if I were to call it almost equal in importance to the first, is to give you sound and philosophical conceptions of the nature and objects of medical science, and of the best methods of attaining these objects. I hope I shall not fail in either of these duties. I may not realize the high ideal of excellence, which rises up before me in my hours of meditation, but 1 trust through diligence on my part, and attention on yours, our time will not be passed unprofitably together. I was about to say, however, that I should deprecate the consequences, upon your future career, of a failure in the second duty, more than of a failure in the first. The phenomena of disease are very extensively recorded—the same is true of their modes of management. These records, to a con- siderable extent, are accessible to you. From these records, and from your own observation, you would soon supply any deficiencies which might exist in my own details, if unhappily any such should exist. But it is impossible to estimate the evils—the obscurity—the confu- sion—the uncertainty—that may attend all your investigations, grow- ing out of a vicious and mistaken conception of your science and its relations. The stream is poisoned at its spring head, and its waters will flow on, turbid and muddy, to the ocean. Lord Bacon, it is well known, added but little to the actual stock of human knowledge: he is not known for any brilliant discoveries:—he made no rich contributions to the treasury of science: he brought no costly gifts to its altar:—but he gave it the great impulse which has carried it te its present proud elevation; and he did this simply by de» fining and demonstrating its true character and objects; and the best and only methods of pursuing them. God forbid that I should be thought so presumptuous as to institute any ridiculous comparison be- tween him and the obscure individual who now addresses you; I claim to be only a humble but earnest disciple of his immortal philosophy. But I am fully persuaded that one of the great needs of our age and our land, so far as medical science is concerned, is a fuller recognition and practice of the true, simple, and rigorous laws of the Baconian philosophy. These laws, although recognized in form, have never, as a general rule, been truly conceived and faithfully followed. It is one of tho most amusing things, in the modern literature of our science, to see how universally this is true. All'the systematists, from Brown to our own countrymen and contemporaries, whom it is not necessary to name, foegin with a dissertation upon the barrenness and the dangers of spec- ulation—upon the importance of adhering to what they call inductive reasoning; and then, forthwith, as though they had satisfied their con- sciences, away they go into the wildest regions of fable and romance. I feel unwilling to close this lecture without making one or two qualifying remarks. I do not wish to indulge anything like a sweeping and indiscriminate condemnation of the spirit of all past medical phi- losophy. I do not forget, that, long ago, medicine had fts Hippocrates, its Morgagni, its Haller, its Sydenham, and that through the labors of these, and of others like them, more or less imbued with the spirit of the Baconian method, there has been gradually building up, for our own use, a noble body of sound and practical wisdom. I have no wish to contemn the reverend fathers of our art. All along the pathway of our science through the ages—tortuous, rugged, enveloped in mist and shadows as it has generally been—here and there, amid the obscurity, have true lights been kindled and set up, shining out on the surrounding darkness with a radiance as serene and steady as that of the everlasting stars. Hearty thanks and high honor be to all those, who from the time of Hippocrates to our own, by diligent observation, have done their parts in making our science and our art what they are. I wish to remark further, that there has never been a time when we had as good cause for self-congratulation as we now have., In the course of this lecture I have expressed myself freely respecting the short-comings and the vices of medical philosophy, and the disastrous results of these upon practical medicine. I have done this from an honest conviction of its truth, and from a strong feeling that in no other way could I do as much service to you. Not less strong than this feeling in regard to the errors of the past, and even of the present, is my conviction of the certain progress and improvement of medicine. The prospect of the future, which presents itself to my contemplation, has more in it of vision than of faith. I have an undoubting confidence, resting alike on the experience of the past and on the essential nature of things, that our science and art are destined to go on in a course of great and almost indefinite advancement. Never before, within the same period of time, during the existence of the science, has it made such rapid and sure progress as for the last forty years. Within the last twenty years, espeeially, have the best minds in the profession been devoting themselves, with a singleness of pur- 17 pose; with a patient industry; with an untiring zeal, and with a lofty and disinterested love of truth, before unequalled—before unknown— to a thorough, comprehensive study of disease. Never before has such searching inquisition been made into the phenomena and relations of morbid action; and never before with such triumphant results. Every where the time is full of the brightest promise, and especially so is it here. Some of the most common, the most violent, and of course the most important and interesting forms of disease, as they occur in and are modified by our own climate and position, are yet to be fully, studied and compared with their cognate and analogous forms abroad. And this can only be done in the spirit Of that philosophy, which it has been the object of this lecture to define. Guided by this philosophy, 1 cannot conceive a richer field than that which is spread out before the American physician. Already have there entered upon it ardent and active laborers, not a few, thoroughly furnished to their work. They are taking possession of its' treasures:—they are writing their names on its history:—they are gathering garlands for their temples, which shall never wither away. Already have some of our young men, even, solved important problems in pathology, which had foiled the skill, and eluded the dexterity of our British brethren.* Happy and fully satisfied shall I be, if I can, even in the slightest degree, be instrumental, in preparing you, either by infusing into your minds the right spirit, or furnishing means to enable you to go forth and occupy, worthily, the rich inheritance which awaits you. As in the direction of all our other relationships—social; moral, economical—the future opens itself before us in two paths, so does it here. One of them, the great and common highway of False Philosophy, is broad well trodden, and shows itself fair to the eye, at its entrance. Flowers blossom along its borders: syren voices sing the safety and the delights of its course—the beauty of the scenery-through which it runs and the grandeur of the Temple of Truth to which it leads. Mul- titudes have thus been led, and multitudes are still led to enter upon this enchanted ground. But the pathway, so pleasant at its beginning, soon loses itself in uncertain wanderings and in a constantly thicken- * Dr. Gerhard, of Philadelphia, was the first to point out the difference, both in -vniDtomd and pathology, between the true British typhus, and the common, con- tinued typhoid fever of ihe United States. In the whole range of practical medicine, there is no single circumstance, which, both to the British and American practitioner, ha- been the occasion of so much obscurity and confusion, as the confounding of these two diseases, resembling each other in many respects, but still differing from each other, as dearly and as distinctly, as measles and scarlatina. c 18 ing obscurity. The melody of the morning outset is soon changed to dissonance. Discordant and jarring voices, issuing from the thousand and one belligerent and angry schools, into which the travellers are divided, make an utter Babel of the place. Every leader of every sect proclaims his own little rush light—kindled at the lantern of some will-o'-the-wisp—and glimmering feebly in the fog—to be the true sun of the medical world; and his own crooked and misty path of the con- fused labyrinth, in whose mazes of cloud and quagmire they all wan- der, to be the only sure and safe road to the truth. The other is the pathway of True Philosophy—in our own science, as in all the rest—narrow and rugged at its entrance, dimly lighted, it may be, and filled with obstacles which it is difficult to surmount. But nevertheless, fear not, and be wise in your choice. This pathway shall widen as you proceed, and every successive step, in your onward and upward career, shall be surer and easier than the last. The light shall brighten as you go on, the earth shall grow firmer under your feet, the heavens shall spread bluer and broader over your heads. The horizon shall widen around you, and every hour shall bring within the scope of your vision objects of new and boundless interest. You will find yourselves, too, in a small, perhaps, but a glorious company, led on, in the far distance, with his flowing beard, and his venerable form, by the old Physician of Cos. It is the path which was trodden by tfie Sydenhams, the Hallers, the Hunters, the Bichats. It is the path which led Harvey to the most brilliant achievement in the annals of physiological science. It is the path which led the more fortunate Jen- ner to th^t disccvery, which has embalmed his name in the gratitude and the love of all countries, and of all times. It is the path which led Newton—clarum et venerabile nomen—up, up, to that loftiest pinnacle ever reached by uninspired humanity, crowned with light of ineffable brightness, where the veil, which, from the creation of the world, had hunf before the universe, hiding its wonder and its mystery, was rent, and man was suffered to look, for the first time, out upon the beauty, the majesty, the unchangeable order, of the handiwork of God. Into this path, and not into the other, be it our effort and our happiness to enter! ► \ -X* ■-.^Jt; * -\ <^ n : ., * * < —• y \ .v N . • < J > •.,, s * \VY*\s,;>/-' J * * • \ \ -\ ■ j • * i ^ t •t^i '* "» . / i yl